System and method for canary deployment using dns srv records

ABSTRACT

Described embodiments provide systems and methods for routing client requests. A device may be arranged intermediary to a plurality of clients and a domain name system (DNS) controller. The device may generate a query for the DNS controller. The query may correspond to a service to be accessed by the clients. The device may receive, from the DNS controller, a response to the query. The response may include a value used by the device to route respective client requests for accessing the service to a corresponding version of a plurality of versions of the service. The device may receive, from a client, a client request for accessing the service. The device may route the client request to one of the versions of the service according to the value included in the response to manage traffic between various versions of the service.

FIELD OF THE DISCLOSURE

The present application generally relates to routing client requests,including but not limited to systems and methods for routing clientrequests to various version(s) of a service.

BACKGROUND

Various services may be used, accessed, or otherwise provided to usersvia their respective client devices. Some services may be updated fromtime to time. For instance, a new version of the service may be deployedfor users to access via their client device. As part of the deploymentof new versions of services, some new versions may perform at less thandesired specifications.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that is further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features, nor is it intended to limit the scope of the claimsincluded herewith.

Systems and methods for routing client requests are described herein.More particularly, the systems and methods described herein leverageservice (SRV) records for configuring an intermediary device orappliance (such as an appliance 200 described above) for routing clientrequests for accessing a service.

An orchestration framework may control the deployment of variousversions of services in a computing environment. Some implementationsmay rely on particular constructs of the orchestration framework todiscover the new versions, implementations, updates, or otherdeployments of such services, and may rely on those same constructs tomarshal the deployments in a language that the intermediary device“understands.” Some proxy implementations may rely on a representationalstate transfer (REST) application programming interfaces (APIs) that maybe published by an orchestration framework to discover the newdeployments. Such REST APIs may vary for endpoint/service discovery anddeployment discovery, and may vary across different orchestrationframeworks, etc. Hence, reliance on REST APIs for detecting and/oridentifying new deployments of services in a computing environment maynot be consistent across multiple platforms, as there may not bestandards governing the format for REST APIs.

According to the implementations and embodiments described herein, thepresent disclosure leverages domain name system (DNS) service (SRV)records for discovery of new deployments, implementations, updates, orother versioning of services in a computing environment. The systems andmethods described herein may implement a universal language which isagnostic to the orchestration framework and, therefore, does not requireany marshalling. By relying on DNS SRV records, which is a language thatmost intermediary devices and appliances are capable of “understanding,”the systems and methods described herein may unify version discovery anddeployment—e.g., using DNS SRV records. Leveraging DNS for deploymentdiscovery may assist in easier and more universal adoption of differenttypes of deployments (e.g., staged or progressive deployment, such as acanary deployment, a blue-green deployment, etc.). With DNS SRV-baseddeployments, any changes to the deployment may be administered withoutsignificant delay, and such changes to the deployment may beadministered in a consistent manner. Furthermore, the appliances can beconfigured and reconfigured with limited to no disturbance in deliveryof content to the corresponding clients. Various other benefits of thesystems and methods described herein will become apparent as follows.

In one aspect, this disclosure is directed to a method. The method mayinclude generating, by a device intermediary to a plurality of clientsand a domain name system (DNS) controller, a query for the DNScontroller. The query may correspond to a service to be accessed by aplurality of clients. The method may include receiving, by the devicefrom the DNS controller, a response to the query. The response mayinclude a value used by the device to route respective client requestsfor accessing the service to a corresponding version of a plurality ofversions of the service. The method may include receiving, by the devicefrom a client of the plurality of clients, a client request foraccessing the service. The method may include routing, by the device,the client request to one of the plurality of versions of the serviceaccording to the value included in the response to manage trafficbetween a first version and a second version of the plurality ofversions of the service.

In some embodiments, the response includes a first priority of the firstversion of the plurality of versions and a second priority of the secondversion of the plurality of versions. In some embodiments, the deviceroutes each of the client requests for accessing the service to one ofthe first version or the second version, based on at least one of thefirst priority of the first version or the second priority of the secondversion. In some embodiments, the response includes a first weight ofthe first version of the plurality of versions and a second weight ofthe second version of the plurality of versions. In some embodiments,the device routes a first portion of the client requests to the firstversion, and a second portion of the plurality of client requests to thesecond version based on at least one of the first weight or the secondweight.

In some embodiments, the method further includes receiving, by thedevice from the DNS controller, an update to the first weight based onone or more monitored conditions of the first version or the secondversions. The method may further include routing, by the device, asecond plurality of client requests for accessing the service based onthe received update to the first weight. In some embodiments, the deviceroutes the second plurality of client requests for accessing the serviceto increase traffic routed to the second version based on the receivedupdate to the first weight. In some embodiments, the response is a firstresponse, the value is a first value, and the method further includesmonitoring, by the device, one or more conditions of one of theplurality of versions. The method may further include transmitting, bythe device, the monitored one or more conditions to the DNS controller.The DNS controller may be configured to transmit a second responseincluding a second value based on the monitored one or more conditions.In some embodiments, the response includes a target domain, a port, apriority, and a weight, and the value is at least one of the priority orthe weight. In some embodiments, the query is a service (SRV) query forthe DNS controller, and the response is an SRV response from the DNScontroller.

In another aspect, this disclosure is directed to a system. The systemmay include a device intermediary to a plurality of clients and a domainname system (DNS) controller. The device may be configured to generate aquery for the DNS controller. The query may correspond to a service tobe accessed by a plurality of clients. The device may be configured toreceive, from the DNS controller, a response to the query. The responsemay include a value used by the device to route respective clientrequests for accessing the service to a corresponding version of aplurality of versions of the service. The device may be configured toreceive, from a client of the plurality of clients, a client request foraccessing the service. The device may be configured to route the clientrequest to one of the plurality of versions of the service according tothe value included in the response to manage traffic between a firstversion and a second version of the plurality of versions of theservice.

In some embodiments, the response includes a first priority of the firstversion of the plurality of versions and a second priority of the secondversion of the plurality of versions. In some embodiments, the deviceroutes each of the client requests for accessing the service to one ofthe first version, or the second version based on at least one of thefirst priority of the first version, or the second priority of thesecond version. In some embodiments, the response includes a firstweight of the first version of the plurality of versions and a secondweight of the second version of the plurality of versions. In someembodiments, the device routes a first portion of the client requests tothe first version and a second portion of the plurality of clientrequests to the second version based on at least one of the first weightor the second weight.

In some embodiments, the device is further configured to receive, fromthe DNS controller, an update to the first weight based on one or moremonitored conditions of the first version or the second version. Thedevice may further be configured to route a second plurality of clientrequests for accessing the service based on the received update to thefirst weight. In some embodiments, the device routes the secondplurality of client requests for accessing the service to increasetraffic routed to the second version based on the received update to thefirst weight. In some embodiments, the response is a first response, thevalue is a first value, and the device is further configured to monitorone or more conditions of one of the plurality of versions. The devicemay further be configured to transmit the monitored one or moreconditions to the DNS controller. The DNS controller may be configuredto transmit a second response, including a second value based on themonitored one or more conditions. In some embodiments, the responseincludes a target domain, a port, a priority, and a weight, and thevalue is at least one of the priority or the weight. In someembodiments, the query is a service (SRV) query for the DNS controller,and the response is an SRV response from the DNS controller.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Objects, aspects, features, and advantages of embodiments disclosedherein will become more fully apparent from the following detaileddescription, the appended claims, and the accompanying drawing figuresin which like reference numerals identify similar or identical elements.Reference numerals that are introduced in the specification inassociation with a drawing figure may be repeated in one or moresubsequent figures without additional description in the specificationin order to provide context for other features, and not every elementmay be labeled in every figure. The drawing figures are not necessarilyto scale, with emphasis instead being placed upon illustratingembodiments, principles, and concepts. The drawings are not intended tolimit the scope of the claims included herewith.

FIG. 1A is a block diagram of a network computing system, in accordancewith an illustrative embodiment;

FIG. 1B is a block diagram of a network computing system for deliveringa computing environment from a server to a client via an appliance, inaccordance with an illustrative embodiment;

FIG. 1C is a block diagram of a computing device, in accordance with anillustrative embodiment;

FIG. 2 is a block diagram of an appliance for processing communicationsbetween a client and a server, in accordance with an illustrativeembodiment;

FIG. 3 is a block diagram of a virtualization environment, in accordancewith an illustrative embodiment;

FIG. 4 is a block diagram of a cluster system, in accordance with anillustrative embodiment;

FIG. 5 is a block diagram of a system for routing client requests, inaccordance with an illustrative embodiment; and

FIG. 6 is a flow diagram of a method for routing client requests, inaccordance with an illustrative embodiment.

DETAILED DESCRIPTION

For purposes of reading the description of the various embodimentsbelow, the following descriptions of the sections of the specificationand their respective contents may be helpful:

Section A describes a network environment and computing environmentwhich may be useful for practicing embodiments described herein;

Section B describes embodiments of systems and methods for delivering acomputing environment to a remote user;

Section C describes embodiments of systems and methods for providing aclustered appliance architecture environment;

Section D describes embodiments of systems and methods for providing aclustered appliance architecture environment; and

Section E describes embodiments of systems and methods for routingclient requests.

A. Network and Computing Environment

Referring to FIG. 1A, an illustrative network environment 100 isdepicted. Network environment 100 may include one or more clients102(1)-102(n) (also generally referred to as local machine(s) 102 orclient(s) 102) in communication with one or more servers 106(1)-106(n)(also generally referred to as remote machine(s) 106 or server(s) 106)via one or more networks 104(1)-104 n (generally referred to asnetwork(s) 104). In some embodiments, a client 102 may communicate witha server 106 via one or more appliances 200(1)-200 n (generally referredto as appliance(s) 200 or gateway(s) 200).

Although the embodiment shown in FIG. 1A shows one or more networks 104between clients 102 and servers 106, in other embodiments, clients 102and servers 106 may be on the same network 104. The various networks 104may be the same type of network or different types of networks. Forexample, in some embodiments, network 104(1) may be a private networksuch as a local area network (LAN) or a company Intranet, while network104(2) and/or network 104(n) may be a public network, such as a widearea network (WAN) or the Internet. In other embodiments, both network104(1) and network 104(n) may be private networks. Networks 104 mayemploy one or more types of physical networks and/or network topologies,such as wired and/or wireless networks, and may employ one or morecommunication transport protocols, such as transmission control protocol(TCP), internet protocol (IP), user datagram protocol (UDP) or othersimilar protocols.

As shown in FIG. 1A, one or more appliances 200 may be located atvarious points or in various communication paths of network environment100. For example, appliance 200 may be deployed between two networks104(1) and 104(2), and appliances 200 may communicate with one anotherto work in conjunction to, for example, accelerate network trafficbetween clients 102 and servers 106. In other embodiments, the appliance200 may be located on a network 104. For example, appliance 200 may beimplemented as part of one of clients 102 and/or servers 106. In anembodiment, appliance 200 may be implemented as a network device such asCitrix networking (formerly NetScaler®) products sold by Citrix Systems,Inc. of Fort Lauderdale, Fla.

As shown in FIG. 1A, one or more servers 106 may operate as a serverfarm 38. Servers 106 of server farm 38 may be logically grouped, and mayeither be geographically co-located (e.g., on premises) orgeographically dispersed (e.g., cloud based) from clients 102 and/orother servers 106. In an embodiment, server farm 38 executes one or moreapplications on behalf of one or more of clients 102 (e.g., as anapplication server), although other uses are possible, such as a fileserver, gateway server, proxy server, or other similar server uses.Clients 102 may seek access to hosted applications on servers 106.

As shown in FIG. 1A, in some embodiments, appliances 200 may include, bereplaced by, or be in communication with, one or more additionalappliances, such as WAN optimization appliances 205(1)-205(n), referredto generally as WAN optimization appliance(s) 205. For example, WANoptimization appliance 205 may accelerate, cache, compress or otherwiseoptimize or improve performance, operation, flow control, or quality ofservice of network traffic, such as traffic to and/or from a WANconnection, such as optimizing Wide Area File Services (WAFS),accelerating Server Message Block (SMB) or Common Internet File System(CIFS). In some embodiments, appliance 205 may be a performanceenhancing proxy or a WAN optimization controller. In one embodiment,appliance 205 may be implemented as Citrix SD-WAN products sold byCitrix Systems, Inc. of Fort Lauderdale, Fla.

Referring to FIG. 1B, an example network environment, 100′, fordelivering and/or operating a computing network environment on a client102 is shown. As shown in FIG. 1B, a server 106 may include anapplication delivery system 190 for delivering a computing environment,application, and/or data files to one or more clients 102. Client 102may include client agent 120 and computing environment 15. Computingenvironment 15 may execute or operate an application, 16, that accesses,processes or uses a data file 17. Computing environment 15, application16 and/or data file 17 may be delivered via appliance 200 and/or theserver 106.

Appliance 200 may accelerate delivery of all or a portion of computingenvironment 15 to a client 102, for example by the application deliverysystem 190. For example, appliance 200 may accelerate delivery of astreaming application and data file processable by the application froma data center to a remote user location by accelerating transport layertraffic between a client 102 and a server 106. Such acceleration may beprovided by one or more techniques, such as: 1) transport layerconnection pooling, 2) transport layer connection multiplexing, 3)transport control protocol buffering, 4) compression, 5) caching, orother techniques. Appliance 200 may also provide load balancing ofservers 106 to process requests from clients 102, act as a proxy oraccess server to provide access to the one or more servers 106, providesecurity and/or act as a firewall between a client 102 and a server 106,provide Domain Name Service (DNS) resolution, provide one or morevirtual servers or virtual internet protocol servers, and/or provide asecure virtual private network (VPN) connection from a client 102 to aserver 106, such as a secure socket layer (SSL) VPN connection and/orprovide encryption and decryption operations.

Application delivery management system 190 may deliver computingenvironment 15 to a user (e.g., client 102), remote or otherwise, basedon authentication and authorization policies applied by policy engine195. A remote user may obtain a computing environment and access toserver stored applications and data files from any network-connecteddevice (e.g., client 102). For example, appliance 200 may request anapplication and data file from server 106. In response to the request,application delivery system 190 and/or server 106 may deliver theapplication and data file to client 102, for example via an applicationstream to operate in computing environment 15 on client 102, or via aremote-display protocol or otherwise via remote-based or server-basedcomputing. In an embodiment, application delivery system 190 may beimplemented as any portion of the Citrix Workspace Suite™ by CitrixSystems, Inc., such as Citrix Virtual Apps and Desktops (formerlyXenApp® and XenDesktop®).

Policy engine 195 may control and manage the access to, and executionand delivery of, applications. For example, policy engine 195 maydetermine the one or more applications a user or client 102 may accessand/or how the application should be delivered to the user or client102, such as a server-based computing, streaming or delivering theapplication locally to the client 120 for local execution.

For example, in operation, a client 102 may request execution of anapplication (e.g., application 16′) and application delivery system 190of server 106 determines how to execute application 16′, for examplebased upon credentials received from client 102 and a user policyapplied by policy engine 195 associated with the credentials. Forexample, application delivery system 190 may enable client 102 toreceive application-output data generated by execution of theapplication on a server 106, may enable client 102 to execute theapplication locally after receiving the application from server 106, ormay stream the application via network 104 to client 102. For example,in some embodiments, the application may be a server-based or aremote-based application executed on server 106 on behalf of client 102.Server 106 may display output to client 102 using a thin-client orremote-display protocol, such as the Independent Computing Architecture(ICA) protocol by Citrix Systems, Inc. of Fort Lauderdale, Fla. Theapplication may be any application related to real-time datacommunications, such as applications for streaming graphics, streamingvideo and/or audio or other data, delivery of remote desktops orworkspaces or hosted services or applications, for exampleinfrastructure as a service (IaaS), desktop as a service (DaaS),workspace as a service (WaaS), software as a service (SaaS) or platformas a service (PaaS).

One or more of servers 106 may include a performance monitoring serviceor agent 197. In some embodiments, a dedicated one or more servers 106may be employed to perform performance monitoring. Performancemonitoring may be performed using data collection, aggregation,analysis, management and reporting, for example by software, hardware ora combination thereof. Performance monitoring may include one or moreagents for performing monitoring, measurement and data collectionactivities on clients 102 (e.g., client agent 120), servers 106 (e.g.,agent 197) or an appliance 200 and/or 205 (agent not shown). In general,monitoring agents (e.g., 120 and/or 197) execute transparently (e.g., inthe background) to any application and/or user of the device. In someembodiments, monitoring agent 197 includes any of the productembodiments referred to as Citrix Analytics or Citrix ApplicationDelivery Management by Citrix Systems, Inc. of Fort Lauderdale, Fla.

The monitoring agents 120 and 197 may monitor, measure, collect, and/oranalyze data on a predetermined frequency, based upon an occurrence ofgiven event(s), or in real time during operation of network environment100. The monitoring agents may monitor resource consumption and/orperformance of hardware, software, and/or communications resources ofclients 102, networks 104, appliances 200 and/or 205, and/or servers106. For example, network connections such as a transport layerconnection, network latency, bandwidth utilization, end-user responsetimes, application usage and performance, session connections to anapplication, cache usage, memory usage, processor usage, storage usage,database transactions, client and/or server utilization, active users,duration of user activity, application crashes, errors, or hangs, thetime required to log-in to an application, a server, or the applicationdelivery system, and/or other performance conditions and metrics may bemonitored.

The monitoring agents 120 and 197 may provide application performancemanagement for application delivery system 190. For example, based uponone or more monitored performance conditions or metrics, applicationdelivery system 190 may be dynamically adjusted, for exampleperiodically or in real-time, to optimize application delivery byservers 106 to clients 102 based upon network environment performanceand conditions.

In described embodiments, clients 102, servers 106, and appliances 200and 205 may be deployed as and/or executed on any type and form ofcomputing device, such as any desktop computer, laptop computer, ormobile device capable of communication over at least one network andperforming the operations described herein. For example, clients 102,servers 106 and/or appliances 200 and 205 may each correspond to onecomputer, a plurality of computers, or a network of distributedcomputers such as computer 101 shown in FIG. 1C.

As shown in FIG. 1C, computer 101 may include one or more processors103, volatile memory 122 (e.g., RAM), non-volatile memory 128 (e.g., oneor more hard disk drives (HDDs) or other magnetic or optical storagemedia, one or more solid state drives (SSDs) such as a flash drive orother solid state storage media, one or more hybrid magnetic and solidstate drives, and/or one or more virtual storage volumes, such as acloud storage, or a combination of such physical storage volumes andvirtual storage volumes or arrays thereof), user interface (UI) 123, oneor more communications interfaces 118, and communication bus 150. Userinterface 123 may include graphical user interface (GUI) 124 (e.g., atouchscreen, a display, etc.) and one or more input/output (I/O) devices126 (e.g., a mouse, a keyboard, etc.). Non-volatile memory 128 storesoperating system 115, one or more applications 116, and data 117 suchthat, for example, computer instructions of operating system 115 and/orapplications 116 are executed by processor(s) 103 out of volatile memory122. Data may be entered using an input device of GUI 124 or receivedfrom I/O device(s) 126. Various elements of computer 101 may communicatevia communication bus 150. Computer 101 as shown in FIG. 1C is shownmerely as an example, as clients 102, servers 106 and/or appliances 200and 205 may be implemented by any computing or processing environmentand with any type of machine or set of machines that may have suitablehardware and/or software capable of operating as described herein.

Processor(s) 103 may be implemented by one or more programmableprocessors executing one or more computer programs to perform thefunctions of the system. As used herein, the term “processor” describesan electronic circuit that performs a function, an operation, or asequence of operations. The function, operation, or sequence ofoperations may be hard coded into the electronic circuit or soft codedby way of instructions held in a memory device. A “processor” mayperform the function, operation, or sequence of operations using digitalvalues or using analog signals. In some embodiments, the “processor” canbe embodied in one or more application specific integrated circuits(ASICs), microprocessors, digital signal processors, microcontrollers,field programmable gate arrays (FPGAs), programmable logic arrays(PLAs), multi-core processors, or general-purpose computers withassociated memory. The “processor” may be analog, digital ormixed-signal. In some embodiments, the “processor” may be one or morephysical processors or one or more “virtual” (e.g., remotely located or“cloud”) processors.

Communications interfaces 118 may include one or more interfaces toenable computer 101 to access a computer network such as a LAN, a WAN,or the Internet through a variety of wired and/or wireless or cellularconnections.

In described embodiments, a first computing device 101 may execute anapplication on behalf of a user of a client computing device (e.g., aclient 102), may execute a virtual machine, which provides an executionsession within which applications execute on behalf of a user or aclient computing device (e.g., a client 102), such as a hosted desktopsession, may execute a terminal services session to provide a hosteddesktop environment, or may provide access to a computing environmentincluding one or more of: one or more applications, one or more desktopapplications, and one or more desktop sessions in which one or moreapplications may execute.

B. Appliance Architecture

FIG. 2 shows an example embodiment of appliance 200. As describedherein, appliance 200 may be implemented as a server, gateway, router,switch, bridge or other type of computing or network device. As shown inFIG. 2, an embodiment of appliance 200 may include a hardware layer 206and a software layer 205 divided into a user space 202 and a kernelspace 204. Hardware layer 206 provides the hardware elements upon whichprograms and services within kernel space 204 and user space 202 areexecuted and allow programs and services within kernel space 204 anduser space 202 to communicate data both internally and externally withrespect to appliance 200. As shown in FIG. 2, hardware layer 206 mayinclude one or more processing units 262 for executing software programsand services, memory 264 for storing software and data, network ports266 for transmitting and receiving data over a network, and encryptionprocessor 260 for encrypting and decrypting data such as in relation toSecure Socket Layer (SSL) or Transport Layer Security (TLS) processingof data transmitted and received over the network.

An operating system of appliance 200 allocates, manages, or otherwisesegregates the available system memory into kernel space 204 and userspace 202. Kernel space 204 is reserved for running kernel 230,including any device drivers, kernel extensions or other kernel relatedsoftware. As known to those skilled in the art, kernel 230 is the coreof the operating system, and provides access, control, and management ofresources and hardware-related elements of application 104. Kernel space204 may also include a number of network services or processes workingin conjunction with cache manager 232.

Appliance 200 may include one or more network stacks 267, such as aTCP/IP based stack, for communicating with client(s) 102, server(s) 106,network(s) 104, and/or other appliances 200 or 205. For example,appliance 200 may establish and/or terminate one or more transport layerconnections between clients 102 and servers 106. Each network stack 267may include a buffer 243 for queuing one or more network packets fortransmission by appliance 200.

Kernel space 204 may include cache manager 232, packet engine 240,encryption engine 234, policy engine 236 and compression engine 238. Inother words, one or more of processes 232, 240, 234, 236 and 238 run inthe core address space of the operating system of appliance 200, whichmay reduce the number of data transactions to and from the memory and/orcontext switches between kernel mode and user mode, for example sincedata obtained in kernel mode may not need to be passed or copied to auser process, thread or user level data structure.

Cache manager 232 may duplicate original data stored elsewhere or datapreviously computed, generated or transmitted to reducing the accesstime of the data. In some embodiments, the cache memory may be a dataobject in memory 264 of appliance 200, or may be a physical memoryhaving a faster access time than memory 264.

Policy engine 236 may include a statistical engine or otherconfiguration mechanism to allow a user to identify, specify, define orconfigure a caching policy and access, control and management ofobjects, data or content being cached by appliance 200, and define orconfigure security, network traffic, network access, compression orother functions performed by appliance 200.

Encryption engine 234 may process any security related protocol, such asSSL or TLS. For example, encryption engine 234 may encrypt and decryptnetwork packets, or any portion thereof, communicated via appliance 200,may setup or establish SSL, TLS or other secure connections, for examplebetween client 102, server 106, and/or other appliances 200 or 205. Insome embodiments, encryption engine 234 may use a tunneling protocol toprovide a VPN between a client 102 and a server 106. In someembodiments, encryption engine 234 is in communication with encryptionprocessor 260. Compression engine 238 compresses network packetsbi-directionally between clients 102 and servers 106 and/or between oneor more appliances 200.

Packet engine 240 may manage kernel-level processing of packets receivedand transmitted by appliance 200 via network stacks 267 to send andreceive network packets via network ports 266. Packet engine 240 mayoperate in conjunction with encryption engine 234, cache manager 232,policy engine 236 and compression engine 238, for example to performencryption/decryption, traffic management such as request-level contentswitching and request-level cache redirection, and compression anddecompression of data.

User space 202 is a memory area or portion of the operating system usedby user mode applications or programs otherwise running in user mode. Auser mode application may not access kernel space 204 directly and usesservice calls in order to access kernel services. User space 202 mayinclude graphical user interface (GUI) 210, a command line interface(CLI) 212, shell services 214, health monitor 216, and daemon services218. GUI 210 and CLI 212 enable a system administrator or other user tointeract with and control the operation of appliance 200, such as viathe operating system of appliance 200. Shell services 214 include theprograms, services, tasks, processes or executable instructions tosupport interaction with appliance 200 by a user via the GUI 210 and/orCLI 212.

Health monitor 216 monitors, checks, reports and ensures that networksystems are functioning properly and that users are receiving requestedcontent over a network, for example by monitoring activity of appliance200. In some embodiments, health monitor 216 intercepts and inspects anynetwork traffic passed via appliance 200. For example, health monitor216 may interface with one or more of encryption engine 234, cachemanager 232, policy engine 236, compression engine 238, packet engine240, daemon services 218, and shell services 214 to determine a state,status, operating condition, or health of any portion of the appliance200. Further, health monitor 216 may determine if a program, process,service or task is active and currently running, check status, error orhistory logs provided by any program, process, service or task todetermine any condition, status or error with any portion of appliance200. Additionally, health monitor 216 may measure and monitor theperformance of any application, program, process, service, task orthread executing on appliance 200.

Daemon services 218 are programs that run continuously or in thebackground and handle periodic service requests received by appliance200. In some embodiments, a daemon service may forward the requests toother programs or processes, such as another daemon service 218 asappropriate.

As described herein, appliance 200 may relieve servers 106 of much ofthe processing load caused by repeatedly opening and closing transportlayer connections to clients 102 by opening one or more transport layerconnections with each server 106 and maintaining these connections toallow repeated data accesses by clients via the Internet (e.g.,“connection pooling”). To perform connection pooling, appliance 200 maytranslate or multiplex communications by modifying sequence numbers andacknowledgment numbers at the transport layer protocol level (e.g.,“connection multiplexing”). Appliance 200 may also provide switching orload balancing for communications between the client 102 and server 106.

As described herein, each client 102 may include client agent 120 forestablishing and exchanging communications with appliance 200 and/orserver 106 via a network 104. Client 102 may have installed and/orexecute one or more applications that are in communication with network104. Client agent 120 may intercept network communications from anetwork stack used by the one or more applications. For example, clientagent 120 may intercept a network communication at any point in anetwork stack and redirect the network communication to a destinationdesired, managed or controlled by client agent 120, for example tointercept and redirect a transport layer connection to an IP address andport controlled or managed by client agent 120. Thus, client agent 120may transparently intercept any protocol layer below the transportlayer, such as the network layer, and any protocol layer above thetransport layer, such as the session, presentation or applicationlayers. Client agent 120 can interface with the transport layer tosecure, optimize, accelerate, route or load-balance any communicationsprovided via any protocol carried by the transport layer.

In some embodiments, client agent 120 is implemented as an IndependentComputing Architecture (ICA) client developed by Citrix Systems, Inc. ofFort Lauderdale, Fla. Client agent 120 may perform acceleration,streaming, monitoring, and/or other operations. For example, clientagent 120 may accelerate streaming an application from a server 106 to aclient 102. Client agent 120 may also perform end-pointdetection/scanning and collect end-point information about client 102for appliance 200 and/or server 106. Appliance 200 and/or server 106 mayuse the collected information to determine and provide access,authentication and authorization control of the client's connection tonetwork 104. For example, client agent 120 may identify and determineone or more client-side attributes, such as: the operating system and/ora version of an operating system, a service pack of the operatingsystem, a running service, a running process, a file, presence orversions of various applications of the client, such as antivirus,firewall, security, and/or other software.

C. Systems and Methods for Virtualizing an Application DeliveryController

Referring now to FIG. 3, a block diagram of a virtualized environment300 is shown. As shown, a computing device 302 in virtualizedenvironment 300 includes a virtualization layer 303, a hypervisor layer304, and a hardware layer 307. Hypervisor layer 304 includes one or morehypervisors (or virtualization managers) 301 that allocates and managesaccess to a number of physical resources in hardware layer 307 (e.g.,physical processor(s) 321 and physical disk(s) 328) by at least onevirtual machine (VM) (e.g., one of VMs 306) executing in virtualizationlayer 303. Each VM 306 may include allocated virtual resources such asvirtual processors 332 and/or virtual disks 342, as well as virtualresources such as virtual memory and virtual network interfaces. In someembodiments, at least one of VMs 306 may include a control operatingsystem (e.g., 305) in communication with hypervisor 301 and used toexecute applications for managing and configuring other VMs (e.g., guestoperating systems 310) on device 302.

In general, hypervisor(s) 301 may provide virtual resources to anoperating system of VMs 306 in any manner that simulates the operatingsystem having access to a physical device. Thus, hypervisor(s) 301 maybe used to emulate virtual hardware, partition physical hardware,virtualize physical hardware, and execute virtual machines that provideaccess to computing environments. In an illustrative embodiment,hypervisor(s) 301 may be implemented as a Citrix Hypervisor by CitrixSystems, Inc. of Fort Lauderdale, Fla. In an illustrative embodiment,device 302 executing a hypervisor that creates a virtual machineplatform on which guest operating systems may execute is referred to asa host server. 302

Hypervisor 301 may create one or more VMs 306 in which an operatingsystem (e.g., control operating system 305 and/or guest operating system310) executes. For example, the hypervisor 301 loads a virtual machineimage to create VMs 306 to execute an operating system. Hypervisor 301may present VMs 306 with an abstraction of hardware layer 307, and/ormay control how physical capabilities of hardware layer 307 arepresented to VMs 306. For example, hypervisor(s) 301 may manage a poolof resources distributed across multiple physical computing devices.

In some embodiments, one of VMs 306 (e.g., the VM executing controloperating system 305) may manage and configure other of VMs 306, forexample by managing the execution and/or termination of a VM and/ormanaging allocation of virtual resources to a VM. In variousembodiments, VMs may communicate with hypervisor(s) 301 and/or other VMsvia, for example, one or more Application Programming Interfaces (APIs),shared memory, and/or other techniques.

In general, VMs 306 may provide a user of device 302 with access toresources within virtualized computing environment 300, for example, oneor more programs, applications, documents, files, desktop and/orcomputing environments, or other resources. In some embodiments, VMs 306may be implemented as fully virtualized VMs that are not aware that theyare virtual machines (e.g., a Hardware Virtual Machine or HVM). In otherembodiments, the VM may be aware that it is a virtual machine, and/orthe VM may be implemented as a paravirtualized (PV) VM.

Although shown in FIG. 3 as including a single virtualized device 302,virtualized environment 300 may include a plurality of networked devicesin a system in which at least one physical host executes a virtualmachine. A device on which a VM executes may be referred to as aphysical host and/or a host machine. For example, appliance 200 may beadditionally or alternatively implemented in a virtualized environment300 on any computing device, such as a client 102, server 106 orappliance 200. Virtual appliances may provide functionality foravailability, performance, health monitoring, caching and compression,connection multiplexing and pooling and/or security processing (e.g.,firewall, VPN, encryption/decryption, etc.), similarly as described inregard to appliance 200.

In some embodiments, a server may execute multiple virtual machines 306,for example on various cores of a multi-core processing system and/orvarious processors of a multiple processor device. For example, althoughgenerally shown herein as “processors” (e.g., in FIGS. 1C, 2 and 3), oneor more of the processors may be implemented as either single- ormulti-core processors to provide a multi-threaded, parallel architectureand/or multi-core architecture. Each processor and/or core may have oruse memory that is allocated or assigned for private or local use thatis only accessible by that processor/core, and/or may have or use memorythat is public or shared and accessible by multiple processors/cores.Such architectures may allow work, task, load or network trafficdistribution across one or more processors and/or one or more cores(e.g., by functional parallelism, data parallelism, flow-based dataparallelism, etc.).

Further, instead of (or in addition to) the functionality of the coresbeing implemented in the form of a physical processor/core, suchfunctionality may be implemented in a virtualized environment (e.g.,300) on a client 102, server 106 or appliance 200, such that thefunctionality may be implemented across multiple devices, such as acluster of computing devices, a server farm or network of computingdevices, etc. The various processors/cores may interface or communicatewith each other using a variety of interface techniques, such as core tocore messaging, shared memory, kernel APIs, etc.

In embodiments employing multiple processors and/or multiple processorcores, described embodiments may distribute data packets among cores orprocessors, for example to balance the flows across the cores. Forexample, packet distribution may be based upon determinations offunctions performed by each core, source and destination addresses,and/or whether: a load on the associated core is above a predeterminedthreshold; the load on the associated core is below a predeterminedthreshold; the load on the associated core is less than the load on theother cores; or any other metric that can be used to determine where toforward data packets based in part on the amount of load on a processor.

For example, data packets may be distributed among cores or processesusing receive-side scaling (RSS) in order to process packets usingmultiple processors/cores in a network. RSS generally allows packetprocessing to be balanced across multiple processors/cores whilemaintaining in-order delivery of the packets. In some embodiments, RSSmay use a hashing scheme to determine a core or processor for processinga packet.

The RSS may generate hashes from any type and form of input, such as asequence of values. This sequence of values can include any portion ofthe network packet, such as any header, field or payload of networkpacket, and include any tuples of information associated with a networkpacket or data flow, such as addresses and ports. The hash result or anyportion thereof may be used to identify a processor, core, engine, etc.,for distributing a network packet, for example via a hash table,indirection table, or other mapping technique.

D. Systems and Methods for Providing a Distributed Cluster Architecture

Although shown in FIGS. 1A and 1B as being single appliances, appliances200 may be implemented as one or more distributed or clusteredappliances. Individual computing devices or appliances may be referredto as nodes of the cluster. A centralized management system may performload balancing, distribution, configuration, or other tasks to allow thenodes to operate in conjunction as a single computing system. Such acluster may be viewed as a single virtual appliance or computing device.FIG. 4 shows a block diagram of an illustrative computing device clusteror appliance cluster 400. A plurality of appliances 200 or othercomputing devices (e.g., nodes) may be joined into a single cluster 400.Cluster 400 may operate as an application server, network storageserver, backup service, or any other type of computing device to performmany of the functions of appliances 200 and/or 205.

In some embodiments, each appliance 200 of cluster 400 may beimplemented as a multi-processor and/or multi-core appliance, asdescribed herein. Such embodiments may employ a two-tier distributionsystem, with one appliance if the cluster distributing packets to nodesof the cluster, and each node distributing packets for processing toprocessors/cores of the node. In many embodiments, one or more ofappliances 200 of cluster 400 may be physically grouped orgeographically proximate to one another, such as a group of bladeservers or rack mount devices in a given chassis, rack, and/or datacenter. In some embodiments, one or more of appliances 200 of cluster400 may be geographically distributed, with appliances 200 notphysically or geographically co-located. In such embodiments,geographically remote appliances may be joined by a dedicated networkconnection and/or VPN. In geographically distributed embodiments, loadbalancing may also account for communications latency betweengeographically remote appliances.

In some embodiments, cluster 400 may be considered a virtual appliance,grouped via common configuration, management, and purpose, rather thanas a physical group. For example, an appliance cluster may comprise aplurality of virtual machines or processes executed by one or moreservers.

As shown in FIG. 4, appliance cluster 400 may be coupled to a firstnetwork 104(1) via client data plane 402, for example to transfer databetween clients 102 and appliance cluster 400. Client data plane 402 maybe implemented a switch, hub, router, or other similar network deviceinternal or external to cluster 400 to distribute traffic across thenodes of cluster 400. For example, traffic distribution may be performedbased on equal-cost multi-path (ECMP) routing with next hops configuredwith appliances or nodes of the cluster, open-shortest path first(OSPF), stateless hash-based traffic distribution, link aggregation(LAG) protocols, or any other type and form of flow distribution, loadbalancing, and routing.

Appliance cluster 400 may be coupled to a second network 104(2) viaserver data plane 404. Similarly to client data plane 402, server dataplane 404 may be implemented as a switch, hub, router, or other networkdevice that may be internal or external to cluster 400. In someembodiments, client data plane 402 and server data plane 404 may bemerged or combined into a single device.

In some embodiments, each appliance 200 of cluster 400 may be connectedvia an internal communication network or back plane 406. Back plane 406may enable inter-node or inter-appliance control and configurationmessages, for inter-node forwarding of traffic, and/or for communicatingconfiguration and control traffic from an administrator or user tocluster 400. In some embodiments, back plane 406 may be a physicalnetwork, a VPN or tunnel, or a combination thereof.

E. Systems and Methods for Routing Client Requests

Systems and methods for routing client requests are described herein.More particularly, the systems and methods described herein leverage SRVrecords for configuring an intermediary device or appliance (such as anappliance 200 described above) for routing client requests to access aservice.

An orchestration framework may control deployment of various versions ofservices in a computing environment. Some implementations may rely onparticular constructs of the orchestration framework to discover the newversions, implementations, updates, or other deployments of suchservices and may rely on those same constructs to marshal thedeployments in a language that the intermediary device “understands.”Some proxy implementations may rely on a representational state transfer(REST) application programming interfaces (APIs) that may be publishedby an orchestration framework to discover the new deployments. Such RESTAPIs may vary for endpoint/service discovery and deployment discovery,may vary across different orchestration frameworks, etc. Hence, Hence,reliance on REST APIs for detecting and/or identifying new deploymentsof services in a computing environment may not be consistent acrossmultiple platforms, as there may not be standards governing the formatfor REST APIs.

According to the implementations and embodiments described herein, thepresent disclosure leverages domain name system (DNS) service (SRV)records for discovery of new deployments, implementations, updates, orother versioning of services in a computing environment. The systems andmethods described herein may implement a universal language which isagnostic to the orchestration framework and, therefore, does not requireany marshalling. By relying on DNS SRV records, which is a language thatmost intermediary devices and appliances are capable of “understanding,”the systems and methods described herein may unify version discovery anddeployment—e.g., using DNS SRV records. Leveraging DNS for deploymentdiscovery may assist in easier and more universal adoption of differenttypes of deployments (e.g., staged or progressive deployment, such as acanary deployment, a blue-green deployment, etc.). With DNS SRV-baseddeployments, any changes to the deployment may be administered withoutsignificant delay, and such changes to the deployment may beadministered in a consistent manner. Furthermore, the appliances can beconfigured and reconfigured with limited to no disturbance in deliveryof content to the corresponding clients. Various other benefits of thesystems and methods described herein will become apparent as follows.

Referring now to FIG. 5, depicted is a block diagram of a system 500 forrouting client requests, according to an illustrative embodiment. Thesystem 500 is shown to include an intermediary device 502 arrangedbetween a plurality of clients 504 and a domain name system (DNS)controller 506. The intermediary device 502 may be configured togenerate a DNS query for the DNS controller 506. The DNS query maycorrespond to a service 510 to be accessed by the clients 504. The DNScontroller 506 may be configured to receive the DNS query, and generatea DNS response for the intermediary device 502. The intermediary device502 may be configured to receive the DNS response from the DNScontroller 506. The DNS response may include a value that is used by theintermediary device 502 to route respective client requests foraccessing the service 510 to a corresponding version of the service 510.The intermediary device 502 may be configured to receive client requestsfrom the client(s) 504. The intermediary device 502 may be configured toroute the client requests to one of the plurality of versions of theservice 510 according to the value from the DNS response from the DNScontroller 506. In this regard, intermediary device 502 may managetraffic between, for instance, a first version 510A and a second version510B of the plurality of versions of the service 510, based on DNSresponses from the DNS controller 506, as described in greater detailbelow.

The systems and methods of the present solution may be implemented inany type or form of device, including clients, servers or appliancesdescribed above with reference to FIG. 1A-FIG. 4. For instance, theintermediary device 502 may be implemented as embodied upon or otherwiseincorporated into an appliance 200 described above with reference toFIG. 2-FIG. 4. The clients 504 may be similar in some respects to theclients 102 described above with respect to FIG. 1A-FIG. 1B. The service510 is shown as being hosted, executed on, or otherwise embodied on aserver 508, which may be similar in some respects to the server 106described above with respect to FIG. 1A-FIG. 1B. In someimplementations, the DNS controller 506 may be embodied upon,incorporated into, or a component of an appliance 200, a server 106,etc. In other words, the intermediary device 502, the clients 504, theDNS controller 506, and/or server 508 may include or incorporatecomponents and devices similar in some aspects to those described abovewith reference to FIG. 1C, such as a memory and/or one or moreprocessors operatively coupled to the memory. The present systems andmethods may be implemented in any embodiments or aspects of theappliances or devices described herein.

As shown in FIG. 5, the system 500 may include a server 508. The server508 is shown to be communicably coupled to the intermediary device 502.In some implementations, the server 508 may be communicably coupled tothe intermediary device 502 via various communication interfaces (e.g.,such as those shown in FIG. 1C and described above). The server 508 mayalso be communicably coupled to the DNS controller 506 via similarcommunications interfaces. While shown as a single server 508, in someimplementations, the system 500 may include a plurality of servers 508.The server(s) 508 may include, maintain, or otherwise host one or moreservices 510. The services 510 may be various types or forms of softwarethat may be provided to the clients 504. In some embodiments, theservice(s) 510 may be or include remote applications, software as aservice (SaaS) applications, etc. The service(s) 510 may enterprisespecific (e.g., services which are specific to a single enterprise,developed by the enterprise, etc.), accessible by a plurality ofdifferent enterprises, etc. In some implementations, the service(s) 510hosted on a server 508 may be a plurality of micro-services. Each of themicro-services may be dedicated to performing a single or a group oftasks. Together, a group of micro-services may form a service 510 whichis provided to a client 504.

In some implementations, the server 508 may include various versions ofa service 510. For instance, as shown in FIG. 5, the server 508 mayinclude a plurality of versions of the service 510 including a firstversion 510A and a second version 510B of a service 510. While twoversions are shown, the server 508 may include any number of versions ofa service 510. An administrator of the service 510 (such as a developer)may manage deployment of such version of the service 510. For instance,the administrator may upload, transmit, send, provide, or otherwisedeploy a second version 510B of the service 510 at the server 508 (e.g.,responsive to developing the second version 510B, responsive to betatesting the second version 510B, etc.). The server 508 may thus host aplurality of versions of the service 510. As described in greater detailbelow, the DNS controller 506 may be configured to control deployment ofthe versions of the service 510 using values in responses to queriesfrom intermediary devices 502.

The system 500 may include the DNS controller 506. The DNS controller506 may be communicably coupled to the intermediary device 502 and/orthe server 508. The DNS controller 506 may be configured to generate,maintain, establish, create, or otherwise include service (SRV) records512 corresponding to service(s) 510 hosted on various servers 508. TheDNS controller 506 may be configured to generate SRV records 512 forservices 510 hosted on the server 508 as new services 510 (and newversions of previous services 510) are deployed at the server 508. Theserver 508 may be configured to register services 510 with the DNScontroller 506 when the services 510 are deployed at the server 508.Hence, as new services 510 are registered with the DNS controller 506,the DNS controller 506 may generate new SRV records 512.

The DNS controller 506 may be configured to generate SRV records 512 foreach of the versions 510A, 510B of the service 510. The DNS controller506 may ping the server 508 (e.g., periodically, responsive tooccurrences of various conditions, etc.) to determine whether newversions of a service 510 have been implemented, included, or otherwisedeployed at the server 508. The DNS controller 506 may be configured togenerate the SRV records 512 based on data corresponding to the service510. For instance, the DNS controller 506 may be configured to structurethe SRV records 512 to include various parameters. The parameters mayinclude a domain name for a service 510, a port corresponding to theservice 510, a weight for the service 510, and a priority for theservice 510. In some implementations, the weight and/or the priority forthe service 510 may be used for allocating and/or routing traffic todifferent versions of a service 510.

The DNS controller 506 may be configured to provide, set, determine, orotherwise generate a value for the SRV records 512. In someimplementations, the DNS controller 506 may be configured to generatethe value for the SRV records 512, to control routing traffic todifferent versions of a service 510. For instance, the DNS controller506 may be configured to generate the value for an SRV record 512corresponding to a first version 510A of a service 510 based ondeployment of a second version 510B of the service 510. In someembodiments, the DNS controller 506 may be configured to generate thevalue based on performance of the first and second versions 510A, 510B.The DNS controller 506 may be configured to receive performance feedbackfrom the server 508 corresponding to execution of the first and secondversion 510A, 510B. The DNS controller 506 may be configured to receivethe performance feedback from the server 506 directly from theintermediary device 502.

The DNS controller 506 may be configured to generate the value byupdating a priority for an SRV record 512. The priority may be used toindicate the priority of one version of the service 510 relative toanother version of the service 510. In some embodiments, the DNScontroller 506 may be configured to set the priority for the firstversion 510A of the service 510 relative to the second version 510B ofthe service 510. The DNS controller 506 may be configured to set thepriority based on an input from a developer of the service 510. The DNScontroller 506 may be configured to set the priority to a defaultpriority based on a new version of the service 510 being registered withthe DNS controller 506. For instance, when a new version of the service510 is deployed at the server 508, the DNS controller 506 mayautomatically set a priority of the new version to a default prioritysuch that network traffic is routed to the new version of the service510. The DNS controller 506 may be configured to set the priority of thesecond version 510B higher than the priority of the first version 510A.The DNS controller 506 may be configured to set the priority of thesecond version 510B to indicate the second version 510B is to receivenetwork traffic from the intermediary device 502. In some embodiments,the DNS controller 506 may be configured to update the priority based onfeedback corresponding to execution of the versions 510A, 510B. Forinstance, the DNS controller 506 may be configured to set the priorityof the second version 510B higher than the first version 510A, such thatnetwork traffic is routed to the second version 510B.

The DNS controller 506 may be configured to receive feedbackcorresponding to execution of the second version 510B of the service510. The DNS controller 506 may be configured to update the prioritybased on the feedback corresponding to execution of the second version510B of the service 510. For instance, the DNS controller 506 may beconfigured to decrease the priority of the second version 510Bresponsive to the feedback indicating unsatisfactory execution of thesecond version 510B (e.g., metrics corresponding to execution of thesecond version 510B being outside of metrics corresponding to executionof the first version 510A). Similarly, the DNS controller 506 may beconfigured to maintain the priority of the second version 510Bresponsive to the feedback indicating satisfactory execution of thesecond version 510B (e.g., metrics corresponding to execution of thesecond version 510B being substantially the same as metricscorresponding to execution of the first version 510A, metricscorresponding to the second version 510B exceeding metrics correspondingto execution of the first version 510A, etc.).

The DNS controller 506 may be configured to generate the value byupdating the weight for an SRV record 512. The weight may be used toindicate a proportion of traffic to be routed to one version of theservice 510 relative to another version of the service 510. In someembodiments, the DNS controller 506 may be configured to set the weightfor the first version 510A of the service 510 relative to the secondversion 510B of the service 510. The DNS controller 506 may beconfigured to set the weight of the first or second version 510A, 510Bof the service 510 based on an input from a developer of the service510. The DNS controller 506 may be configured to set the weight to adefault weight based on a new version of the service 510 beingregistered with the DNS controller 506. For instance, when a new versionof the service 510 is deployed at the server 508, the DNS controller 506may automatically set a weight of the new version to a default prioritysuch that a small portion of the network traffic is routed to the newversion of the service 510 (as compared to the previous version of theservice 510). As described in greater detail below, the DNS controller506 may update the weight for the new version to increase networktraffic to the new version over time.

The DNS controller 506 may be configured to set the weight of the secondversion 510B higher than the weight of the first version 510A. The DNScontroller 506 may be configured to set the weight of the second version510B to indicate the second version 510B is to receive a higher portionof network traffic from the intermediary device 502 than the firstversion 510A of the service 510. In some embodiments, the DNS controller506 may be configured to update the weight based on feedbackcorresponding to execution of the versions 510A, 510B. For instance, theDNS controller 506 may be configured to set the weight of the secondversion 510B higher than the first version 510A such that more networktraffic is routed to the second version 510B.

The DNS controller 506 may be configured to receive feedbackcorresponding to execution of the second version 510B of the service510. The DNS controller 506 may be configured to update the weight basedon the feedback corresponding to execution of the second version 510B ofthe service 510. For instance, the DNS controller 506 may be configuredto decrease the weight of the second version 510B responsive to thefeedback indicating unsatisfactory execution of the second version 510B(e.g., metrics corresponding to execution of the second version 510Bbeing outside of metrics corresponding to execution of the first version510A). Similarly, the DNS controller 506 may be configured to increasethe weight of the second version 510B responsive to the feedbackindicating satisfactory execution of the second version 510B (e.g.,metrics corresponding to execution of the second version 510B beingsubstantially the same as metrics corresponding to execution of thefirst version 510A, metrics corresponding to the second version 510Bexceeding metrics corresponding to execution of the first version 510A,etc.).

As described in greater detail below, the DNS controller 506 may beconfigured to transmit, send, or otherwise provide an SRV response to anintermediary device 502 (e.g., responsive to receiving an SRV query fromthe intermediary device 502). The DNS controller 506 may be configuredto provide the value (e.g., the weight and/or priority) to theintermediary device 502 to control network traffic between respectiveversions of the service 510.

The system 500 is shown to include an intermediary device 502. Theintermediary device 502 may be arranged intermediary to the clients 504and a DNS controller 506. The intermediary device 502 may be similar insome respects to the appliance 200 described above with reference toFIG. 2 and FIG. 4. The intermediary device 502 may be communicablycoupled to the client(s) 504, DNS controller 506, and server(s) 508. Theintermediary device 502 may facilitate communications between theclient(s) 504 and server(s) 508. The intermediary device 502 may beconfigured to generate queries for the DNS controller 506. Theintermediary device 502 may be configured to generate the queries forthe DNS controller 506 at various intervals (e.g., once a minute, oncean hour, once a day, once a week, etc.) responsive to one or moreconditions (e.g., responsive to receiving a client request for a service510, responsive to receiving a notification or ping from a server 508hosting a service 510, responsive to receiving a notification or pingfrom a device corresponding to an administrator or service developer,etc.). The intermediary device 502 may be configured to generate a querycorresponding to a service 510 for managing network traffic betweendifferent versions of the service 510, as described in greater detailbelow.

In some embodiments, the request may be a service (SRV) query. The SRVquery may include, for instance, a target domain for the service 510,among other information. The intermediary device 502 may be configuredto generate the SRV query for the DNS controller 506. The intermediarydevice 502 may be configured to generate the SRV query to request theparameters from the SRV record 512 corresponding to the service 510 fromthe DNS controller 506. The intermediary device 502 may be configured totransmit the SRV query to the DNS controller 506. The intermediarydevice 502 may be configured transmit the SRV query to the DNScontroller 506 via a wireless or wired communications link between theDNS controller 506 and intermediary device 502. The DNS controller 506may perform a look-up using data from the SRV query (e.g., the targetdomain, for instance) in the SRV records 512 to identify a correspondingSRV record 512. The DNS controller 506 may be configured to transmit aSRV response corresponding to the SRV request. The SRV response mayinclude, for instance, the target domain, the port, the weight, thepriority, etc. In some embodiments, the SRV response may include datacorresponding to a plurality of SRV records for the same target domain.For instance, the DNS controller 506 may be configured to include datacorresponding to the SRV record 512 for the first version 510A and datacorresponding to the SRV record 512 for the second version 510B of theservice 510. The intermediary device 502 may be configured to use thevalues from the SRV response to control network traffic between theversions of the service 510.

The intermediary device 502 may be configured to receive the SRVresponse from the DNS controller 506. The SRV response may include avalue used by the intermediary device 502 to route client requests toversions of a service 510. The intermediary device 502 may be configuredto parse the SRV response from the DNS controller 506 to identifyvalue(s) corresponding to services 510 that are accessible by clients504. The intermediary device 502 may be configured to use the identifiedvalues for generating a configuration setting for the intermediarydevice 502. The configuration setting may be a setting which configuresnetwork routing of client requests to respective versions of the service510.

In some instances, the SRV response may include a weight of a firstversion 510A and a weight of a second version 510B of the service. Theintermediary device 502 may be configured to identify the weight of thefirst version 510A and the weight of the second version 510B. Theintermediary device 502 may be configured to determine a proportion,ratio, etc. of the weight of the first version 510A and the weight ofthe second version 510B. The intermediary device 502 may be configuredto generate a configuration setting which allocates a portion of clientrequests to the first version 510A and another portion of clientrequests to the second version 510B (e.g., based on the proportion/ratioof the weights). The intermediary device 502 may be configured todistribute, transmit, send, or otherwise provide client requests to thefirst and second versions 510A, 510B (e.g., at the port specified intheir corresponding SRV records) in accordance with the ratio of theweights. For instance, the proportion of the weight of the secondversion 510B to the weight of the first version 510A may be 2/1. Theintermediary device 502 may be configured to generate a configurationsetting for the intermediary device 502 to allocate two-thirds of clientrequests to the second version 510B and one third of the client requeststo the first version 510A.

In some instances, the SRV response may include a priority of a firstversion 510A and a priority of a second version 510B of the service. Theintermediary device 502 may be configured to identify the priority ofthe first version 510A and the priority of the second version 510B. Theintermediary device 502 may be configured to determine which of thefirst version 510A and the second version 510B has a higher priority.The intermediary device 502 may be configured to generate aconfiguration setting which allocates each of the client requests to thefirst version 510A or the second version 510B based on the version 510A,510B having the highest priority. The intermediary device 502 may beconfigured to distribute, transmit, send, or otherwise provide clientrequests to one of the first or second versions 510A, 510B (e.g., at theport specified in their corresponding SRV records) having the highestpriority.

The system 500 is shown to include a plurality of clients 504. Theclients 504 may be similar to the clients 102 described above. Theclients 504 may be personal computers, laptops, desktops, tablets,mobile devices, etc. The clients 504 may be configured to accessservices 510 hosted on the servers 508. The clients 504 may beconfigured to access the services 510 by generating client requests forthe intermediary device 502 (e.g., client requests to access the service510). The clients 504 may be configured to generate the client requestswhen a user selects a service 510, launches a service 510, the client504 is turned on, etc. The client request may include, for instance, atarget domain (e.g., a domain corresponding to the service 510endpoint). The clients 504 may be configured to transmit, send, orotherwise provide the client requests to the intermediary device 502 forrouting to a corresponding version of the service 510.

The intermediary device 502 may be configured to receive client requestsfrom the clients 504 for accessing the service 510. The intermediarydevice 502 may be configured to determine a configuration settingcorresponding to the target domain specified in the client request. Forinstance, the intermediary device 502 may be configured to determinewhether the target domain specified in a particular client requestcorresponds to a configuration setting for an SRV record 512. Theintermediary device 502 may be configured to route the client requestsbased on the configuration setting. For instance, where theconfiguration setting specifies routing a portion of client requests toa first version 510A and a portion of client requests to a secondversion 510B (e.g., based on the respective weights from the SRVresponse from the DNS controller 506), the intermediary device 502 maybe configured to route the client requests received from the clients 504based on the corresponding configuration setting. As another example,where the configuration setting specifies routing each of the clientrequests to one of the versions 510 of the service (e.g., based on therespective priority from the SRV response from the DNS controller 506),the intermediary device 502 may be configured to route the clientrequests received from the clients 504 based on the correspondingconfiguration setting.

In some embodiments, the intermediary device 502 may be configured tomonitor the execution of the corresponding version(s) 510A, 510B of theservice 510. The intermediary device 502 may be configured to monitorexecution of the versions 510A, 510B to determine various conditions ofthe execution. The conditions may include, for instance, error rate,latency, traffic rate, etc. The intermediary device 502 may beconfigured to transmit, send, or otherwise provide the conditions to theDNS controller 506 as feedback. In some embodiments, the server 508 maybe configured to monitor the execution of the corresponding version(s)510A, 510B of the service 510 to determine conditions of the execution.The server 508 may be configured to transmit, send, or otherwise providethe conditions to the DNS controller 506 as feedback. In these and otherembodiments, the DNS controller 506 may be configured to receivefeedback corresponding to execution of the version(s) 510A, 510B of theservice 510.

The DNS controller 506 may be configured to maintain, include, orotherwise access thresholds corresponding to execution of version(s)510A, 510B of the service 510. For instance, the DNS controller 506 maybe configured to access thresholds corresponding to conditions forexecution of a previous version of the service 510. The DNS controller506 may be configured to compare the thresholds corresponding to aprevious version of the service 510 with monitored conditionscorresponding to execution of a new version of the service 510. The DNScontroller 506 may be configured to update the SRV records based on thefeedback corresponding to the monitored conditions corresponding toexecution of the version(s) 510A, 510B, based on the comparison to thethresholds, etc.

The DNS controller 506 may be configured to update the SRV records toincrease the weight of (or increase the priority of) the second version510B relative to the first version 510A where the monitored conditionsof the second version 510B satisfy thresholds corresponding to theexecution of the first version 510A. The monitored conditions of thesecond version 510B may satisfy the thresholds where the conditionscorresponding to execution of the second version 510B are substantiallythe same as (or are improved with respect to) execution of the firstversion 510A (e.g., decreases in or substantially the same error rate,decreases in or substantially the same latency, improved orsubstantially the same traffic rates, etc.). Similarly, the DNScontroller 506 may be configured to update the SRV records to decreasethe weight of (or decrease the priority of) the second version 510Brelative to the first version 510A when the monitored conditions of thesecond version 510B do not satisfy thresholds corresponding to theexecution of the first version 510A. The monitored conditions of thesecond version 510B may not satisfy the thresholds where the conditionscorresponding to execution of the second version 510B are not improvedwith respect to execution of the first version 510A (e.g., increases inerror rate, increases in latency, decreases in traffic rate, etc.).

Similar to the first SRV response, the DNS controller 506 may beconfigured to send a second SRV response to the intermediary device 502.The DNS controller 506 may be configured to send the second SRV responsein response to an SRV query, when the DNS controller 506 updates the SRVrecord 512, etc. The intermediary device 502 may be configured to routesubsequent client requests according to the updates to theweight/priority as indicated in the SRV response. The intermediarydevice 502 may be configured to update the configuration setting andtransmit subsequent client requests according to the updatedconfiguration setting.

Referring to FIG. 6, depicted is a flowchart showing a method 600 ofrouting client requests according to an illustrative embodiment. Themethod 600 (including various steps included therein) may be implementedby one or more of the components shown in FIG. 5 and described above,such as the intermediary device 502, the client(s) 504, the DNScontroller 506, and/or server 508. As a brief overview, at step 602, adevice generates a query. At step 604, the device receives a response.At step 606, the device receives a client request. At step 608, thedevice routes the request according to the response.

At step 602, and in some embodiments, a device generates a query. Insome embodiments, the device is intermediary to a plurality of clientsand a domain name system (DNS) controller. The device may generate aquery for the DNS controller. The query may correspond to a service tobe accessed by a plurality of clients. The device may generate andtransmit the query to the DNS controller. The device may generate thequery at various intervals (e.g., once a minute, once an hour, once aday, once a week, etc.). In this regard, the device may generate thequery independent of client requests corresponding to the service. Thedevice may generate the query responsive to receiving a client requestfor the corresponding service. In some embodiments, the query may be aservice (SRV) query. The SRV query may query the DNS controller forinformation corresponding to the service. The device may query the DNScontroller for information corresponding to the service to determinewhether there are any updates or new versions for the service.

At step 604, and in some embodiments, the device receives a response. Insome embodiments, the device may receive a response to the query fromthe DNS controller. The response may include a value used by the deviceto route respective client requests for accessing the service to acorresponding version of a plurality of versions of the service. The DNScontroller may identify the value based on data included in an SRVrecord maintained by the DNS controller for the service. The DNScontroller may use the query (e.g., generated at step 602) foridentifying the SRV record corresponding to the service. For instance,the SRV record may include a target domain, and the query may include atarget domain. The DNS controller may perform a look-up function usingthe target domain from the query for identifying a target domain in acorresponding SRV record. The DNS controller may generate and transmit aresponse using the identified SRV record. The response may be an SRVresponse including data from the SRV records.

In some embodiments, the response includes a target domain, a port, apriority, and a weight. The DNS controller may generate, set, orotherwise assign the priority and/or the weight to modify, regulate, orotherwise control the network traffic between versions of a serviceprovided to the client(s). The DNS controller may assign a value to thepriority and/or weight for the SRV record. The DNS controller may assignthe value to the priority and/or weight for the SRV record when a newversion of a service corresponding to the service is deployed, based onan input from an administrator corresponding to the service, based onfeedback corresponding to monitored conditions of the execution of theservice, etc. The DNS controller may assign the value to the priorityand/or weight to increase traffic to one version while correspondinglydecreasing traffic to another version. As described in greater detailbelow, the DNS controller may update the priority weight over time(e.g., based on feedback corresponding to monitored conditions ofexecution of one or more version(s) of the service).

The response may be or include data corresponding to a plurality of SRVrecords for respective versions of the service. For instance, theresponse may include data corresponding to an SRV record for a firstversion of the service and data corresponding to an SRV record for asecond version of the same service. In some embodiments, the responseincludes a first priority of a first version and a second priority of asecond version. In some embodiments, the response includes a firstweight of the first version and a second weight of the second version.As described in greater detail below, the respective priorities and/orrespective weights may be used (e.g., by the intermediary device) forrouting network traffic between the first and second version of theservice.

At step 606, and in some embodiments, the device receives a clientrequest. In some embodiments, the device may receive a client requestfor accessing the service from a client of the plurality of clients. Thedevice may receive the client request over a network which connects thedevice to the client(s). In some embodiments, the device may receive aplurality of client requests. The device may determine a port of aserver for which to route the client requests received at step 606, asdescribed in greater detail below.

At step 608, and in some embodiments, the device routes the requestaccording to the response. In some embodiments, the device may route therequest to one of the plurality of versions of the service according tothe value included in the response to manage traffic between the firstversion and the second version. The device may route the requestaccording to the value included in the response. In some embodiments,the device routes each of the requests for accessing the service to oneof the first version or the second version based on at least one of thefirst priority of the first version or the second priority of the secondversion. For instance, where the response includes a priority of thesecond version which is higher than a priority of the first version, thedevice may route each of the client requests to a port corresponding tothe second version (as the second version has a higher priority). Insome embodiments, the device routes a first portion of the requests tothe first version and a second portion of the plurality of requests tothe second version based on at least one of the first weight or thesecond weight. For instance, where the response includes a weight of thesecond version and a weight of the first version, the device may route aportion of client requests to the port corresponding to the secondversion and a portion of client requests to the port corresponding tothe first version. The portions for the first and second version may bein proportion to the weight of the second version to the weight of thefirst version.

In some embodiments, the response (e.g., received at step 604) may be afirst response and the value may be a first value. The device maymonitor one or more conditions of one (or more) of the plurality ofversions. For instance, where the device routes client requests inproportion to the weights, the device may monitor conditionscorresponding to executing the respective versions. The device maytransmit the monitored one or more conditions to the DNS controller. TheDNS controller may be configured to transmit a second response includinga second value based on the monitored one or more conditions.

In some embodiments, the device may receive an update to the firstweight from the DNS controller. The device may receive the update basedon one or more monitored conditions of the first version or the secondversion. The device may monitor the conditions of the first or secondversion, the server hosting the version(s) of the service may monitorthe conditions, the DNS controller may monitor the conditions, etc. Thedevice may route a second plurality of requests for accessing theservice based on the received update to the first weight. In someembodiments, the device routes the second plurality of requests foraccessing the service, to increase traffic routed to the second versionbased on the received update to the first weight.

Various elements, which are described herein in the context of one ormore embodiments, may be provided separately or in any suitablesub-combination. For example, the processes described herein may beimplemented in hardware, software, or a combination thereof. Further,the processes described herein are not limited to the specificembodiments described. For example, the processes described herein arenot limited to the specific processing order described herein and,rather, process blocks may be re-ordered, combined, removed, orperformed in parallel or in serial, as necessary, to achieve the resultsset forth herein.

It will be further understood that various changes in the details,materials, and arrangements of the parts that have been described andillustrated herein may be made by those skilled in the art withoutdeparting from the scope of the following claims.

We claim:
 1. A method, comprising: generating, by a device intermediaryto a plurality of clients and a domain name system (DNS) controller, aquery for the DNS controller, the query corresponding to a service to beaccessed by a plurality of clients; receiving, by the device from theDNS controller, a response to the query, the response including a valueused by the device to route respective client requests for accessing theservice to a corresponding version of a plurality of versions of theservice; receiving, by the device from a client of the plurality ofclients, a client request for accessing the service; and routing, by thedevice, the client request to one of the plurality of versions of theservice according to the value included in the response to managetraffic between a first version and a second version of the plurality ofversions of the service.
 2. The method of claim 1, wherein the responseincludes a first priority of the first version of the plurality ofversions and a second priority of the second version of the plurality ofversions.
 3. The method of claim 2, wherein the device routes each ofthe client requests for accessing the service to one of the firstversion or the second version based on at least one of the firstpriority of the first version or the second priority of the secondversion.
 4. The method of claim 1, wherein the response includes a firstweight of the first version of the plurality of versions and a secondweight of the second version of the plurality of versions.
 5. The methodof claim 4, wherein the device routes a first portion of the clientrequests to the first version and a second portion of the plurality ofclient requests to the second version based on at least one of the firstweight or the second weight.
 6. The method of claim 5, furthercomprising: receiving, by the device from the DNS controller, an updateto the first weight based on one or more monitored conditions of thefirst version or the second version; and routing, by the device, asecond plurality of client requests for accessing the service based onthe received update to the first weight.
 7. The method of claim 6,wherein the device routes the second plurality of client requests foraccessing the service, to increase traffic routed to the second versionbased on the received update to the first weight.
 8. The method of claim1, wherein the response is a first response, the value is a first valueand further comprising: monitoring, by the device, one or moreconditions of one of the plurality of versions; and transmitting, by thedevice, the monitored one or more conditions to the DNS controller, theDNS controller configured to transmit a second response including asecond value based on the monitored one or more conditions.
 9. Themethod of claim 1, wherein the response includes a target domain, aport, a priority, and a weight, and wherein the value is at least one ofthe priority or the weight.
 10. The method of claim 1, wherein the queryis a service (SRV) query for the DNS controller, and wherein theresponse is an SRV response from the DNS controller.
 11. A system,comprising: a device intermediary to a plurality of clients and a domainname system (DNS) controller, the device configured to: generate a queryfor the DNS controller, the query corresponding to a service to beaccessed by a plurality of clients; receive, from the DNS controller, aresponse to the query, the response including a value used by the deviceto route respective client requests for accessing the service to acorresponding version of a plurality of versions of the service;receive, from a client of the plurality of clients, a client request foraccessing the service; and route the client request to one of theplurality of versions of the service according to the value included inthe response to manage traffic between a first version and a secondversion of the plurality of versions of the service.
 12. The system ofclaim 11, wherein the response includes a first priority of the firstversion of the plurality of versions and a second priority of the secondversion of the plurality of versions.
 13. The system of claim 12,wherein the device routes each of the client requests for accessing theservice to one of the first version or the second version based on atleast one of the first priority of the first version or the secondpriority of the second version.
 14. The system of claim 11, wherein theresponse includes a first weight of the first version of the pluralityof versions and a second weight of the second version of the pluralityof versions.
 15. The system of claim 14, wherein the device routes afirst portion of the client requests to the first version and a secondportion of the plurality of client requests to the second version basedon at least one of the first weight or the second weight.
 16. The systemof claim 15, wherein the device is further configured to: receive, fromthe DNS controller, an update to the first weight based on one or moremonitored conditions of the first version or the second version; androute a second plurality of client requests for accessing the servicebased on the received update to the first weight.
 17. The system ofclaim 16, wherein the device routes the second plurality of clientrequests for accessing the service, to increase traffic routed to thesecond version based on the received update to the first weight.
 18. Thesystem of claim 11, wherein the response is a first response, the valueis a first value and wherein the device is further configured to:monitor one or more conditions of one of the plurality of versions; andtransmit the monitored one or more conditions to the DNS controller, theDNS controller configured to transmit a second response including asecond value based on the monitored one or more conditions.
 19. Thesystem of claim 11, wherein the response includes a target domain, aport, a priority, and a weight, and wherein the value is at least one ofthe priority or the weight.
 20. The system of claim 11, wherein thequery is a service (SRV) query for the DNS controller, and wherein theresponse is an SRV response from the DNS controller.